Distant pneumatic control for a drilling rig



Nov. 23, 1937. M A. CAPELIUSHNICOFF ET AL 2,

I DTSTANT PNEUMATIC CONTROL FOR A DRILLTNG RIG Filed Dec. 3, 1934Patented Nov. 23, 1937 i1 [T E 'TT E BISTANT PNEUMATIC GONTROL FOR ADRILLING RIG Matvey Alcunovitch Capeliushnicoff and Semien LvovitchZalkin, Baku, Union of Soviet Socialist Republics ber 28, 1933 3 Claims.

The control of a powerful winch of a drilling rig, which is providedwith a band brake (or block brake) and with claw couplings (or frictionclutches) for speed changing, is usually effected 5 by means of a systemof levers differingfrom one another in all types of winches only intheir construction. Such an imperfect control requires the expenditureof great muscular strength, results in very slow operation of the rigand causes heavy and collective traumatic injuries. The operator, onwhose skill and attention depends the success of boring, must work underdiificult conditions, under heavy joltings, the rattling noise of therig, with great-physical strain and in an inconvenient and tiresomeposture. Effective operationis only possible at the expense -.of greatphysical effort of the operators (when sinking or lifting the tools invery deep bores). On the other hand these relatively few operationsrequire a substantial number of operators who cannot be utilized Whollyin the boring process.

The overcoming of these drawbacks of a drilling rig manipulation is onlypossible by means of mechanization of the braking operations and of theoperations of engaging the claw couplings and of some other operations;

Numerous attempts to provide the mechanical control of winches ofdrilling rigs by means of various hydraulic electric pneumatic meanshave proved unsuccessful owing to increased demands on the brake of thewinch of a drilling rig. The main requirements are as follows:

' 1. The brake must be absolutely safe. 'In all cases of injuries orfaults of installing or of un- 5 skilled handling the brake must alwaysmaintain a sufficient braking power to prevent accident.

2. The brake must be absolutely controllable to ensure a highlyeffective boring operation. Each position of the controlling valvehandle must cor- 40 respond to a definite braking power, which must beautomatically maintained for an indefinitely long period of time inspite of leakages or the like. The braking power must change graduallyat the same rate that the valve handle is moved.

3. The brake must be reliable in service, not requiring much attention,it must be simple in its assembling and cheap in production.

- All these requirements are fulfilled according to the present systemof the distant pneumatic control for drilling rigs, comprising a noveldouble-chamber automatic brake for the winch and control means forthrowing in the claw couplings.

In order'that the invention may be more fully 65 understood and carriedinto effect it will now be described with reference to the accompanyingdrawing in which:

Figure 1 shows diagrammatically and partly in detail an arrangement forthe distant control of a drilling rig by means of a two-chamber auto- 5matic brake, and for the automatic engaging of the claw couplings forspeed changing.

Figures 2 and 3 are detail views of the auxiliary valve for the controlof the claw couplings.

The two-chamber automatic brake for the 10 winch comprises a brakecylinder I in which travels a piston with a two-sided leather packingsleeve 2. The piston is guidedby means of a tubular piston rod i. Withinthe latter is located a rocking rod 6. The rod 6 is pivotally connected15 to the crank 7 attached to the shaft of the brake handle 8. If theshaft of the handle 8 is turned,

it applies the brake bands 3 to the winch drum 3a.

A chain 9 is attached to the upper end of the crank l and passes roundthe roller Ill, the other 0 end of this chain being attached to theweight II. This weight II is attached to the rod [2 of a piston in theair cylinder H3.

The first and main distinction of this brake from any pneumatic brakesknown heretofore 5 consists therein that in its normal working posi-'tion this brake always tends to effect full braking by means of aseparate and definite volume of compressed air, which constantly pressesdirectly on one side of the piston 2 of the brake cylinder 1, thispressure being maintained constant by means of a separate pressureregulating device It. The non-return valve i5 prevents this volume ofair from flowing back into the air pipe-line.

Said result is obtained by means of the brake cylinder l which isdivided by the piston 2 into two chambers: the braking chamber A and thereleasing chamber B. The braking chamber communicates with the reservoirM having a determinate volume, in which the pressure is 40 maintainedconstant by means of the regulating device it, ,said' pressure beinglower than in the main reservoir I8. The non-return valve ltprevents theair from flowing back in the case of pressure drop in the main reservoirl8. 45

The pressure in the braking chamber A and in the reservoir I4 ismaintained always constant whether the brake is applied or released. Thedisplacement of the piston 2 in the chamber A causes only minorexpansion 'orpcompression of 50 air. All leakages of air in the systemare compensated for by the regulating device l6. If the feeding of freshcompressed air into the system is interrupted, the pressure requiredforbraking will be maintained for a sufilcient period of time .of theshaft carrying the brake handle 8.

pressure in the braking chamber A can fall only to a predeterminedlimit, because on attaining,

this critical low pressure, the weight M will descend and compress theair and so maintain a certain pressure and at the same .time it willtighten the chain 9, so that the braking will be effected Wholly orpartially by'the falling by gravity of the load l I. (For example, ifthe normal pressure in the braking chamber A? is 3.2 atm., the workingarea of the piston i2 is 50 sq. cm., and the weight of the load H is kg.then. the force 50 3.2=160 kg. will move the .load II upwards. Thepressure may fall only to 3 atm. when the upwardly directed force actingon the load II will be equal to the weight of this load. A furtherdecrease of the pressure and of thebraking effect is impossible as theair will be compressed by the weight of load H.)

For releasing the brake it is necessary to displace the piston 2 to theleft, and this may be done only by raising the pressure in the releasingchamber B. The inlet of air into the releasing chamber B for releasingthe brake is efiected by means of V a regulating valve l7. Thus forbraking, the air must be let out from the cham ber B through the pipe 32by means of the Valvefl'l of the type shown and described in U. S.Patent No. 1,657,400, and conversely for releasing the brake, the airmust be admitted into the chamber B by the same valvef from, the mainreservoir 18, where the pressure is higher than in the reservoir it,Each position of the handle of the valve i1 corresponds to a definitevalue of pressure in the releasing chamber B and consequently determinesthe braking effect. valve I1 is a form of the known railwayautomaticstraight-acting brake valve of the type shown in the above-mentioned U.S. patent.

In the air conducting pipe 32 between the releasing chamber B and thevalve i7 is inserted an accelerating valve. which comprises the casing29, the slide Valve 39 and the piston 3|.

The operation of the accelerating valve 29 is as follows:- r r When thehandle of the valve I! is being turned slowly (slow braking), that'is tosay, when the valve I1 lets the air escape slowly and in smallquantities from the chamber B into the atmosphere, then air hassufficient time to pass through the small calibrated openings in thepiston 3| without displacing this piston. If the handle is turned fast(quick braking), that is to say, when air es capes rapidly and in largequantities from the chamber B of the braking cylinder l into theatmosphere, the air has not time enough top a ss through the openings ofthe piston 3! and the pressure below this piston drops beyond thepressure in the chamber B. Then the piston 3! 30.. The slide valve 30opens the port C. prc- Vided in the casing 29 thus permitting the air toescape quickly into the atmosphere and pro; 7

moting a very. rapid braking.

The

" ied by the releaseof the brake.

The principle of operation of the double-chamber automatic brake. forthe winches is as follows:

The compressed air having a predetermined constant pressure (3.5 atm.)maintained in the reservoir Hi and in the chamber A by means of thepressure regulator (reduction valve) [5 presses immediately against thepiston 2 of the brake cylinder i. This effort is transmitted through thepiston-rod to the crank I which latter turns the handle 8 and appliesthe brake bands, so that braking takes place.

In order to release the brake the pressure must be increased in therelease chamber B by means of the main valve Ill. The eiiective area ofthe chamber B being smaller than the area of of the chamber A (a portionof this area being occupied by the piston-rod 4), it is necessary inorder to fully release the brake to increase the pressure in the chamberB making it about 0.3-0.5 atm. higher than the pressure in the chamberA. The control valve ll is adjusted in such a manner, that whileitshandle is in its extreme left position the required excess of pressureis obtained, and consequently the full release takes place. If thepressure in the main air reservoir drops under its normal value (4-5atm.) but does not fall below the pressure in the reservoir i i, thebraking mechanical effort will be in no way reduced, but a full releaseof the brake becomes impossible. Sinceit will be impossible in this caseto create by means of the valve H a pressure in the chamber B which willbe higher than in the chamber A and in the reservoir it, so that thesinking'of light tools (such as a hook, one rod, four tubes or the like)will be impededand all sinking and lifting opera-' tions obstructed.This phenomenon will serve as aquite sure signal showing that thereexists an abnormal drop of pressure in'the main reservoir and that thefurther gradual release of the brake will be dangerous.

- The working pressure existing in the reservoir l4 and in thechamber Ais also maintained (by means of the pipe 34) in the weight-loaded cyleinder It, so that the weight M is forced toremain in'its upper positionIn this case the un: tightened chain 9 lies loosely on the roller I0 anddoes not hinder the turning of the crank 1' I and the normal process ofreleasing or applying of the brake. If the pressure in the mainreservoir 58 drops; the pressure in the brake cylinder'still' subsistsfor a long'whiledue to the check valve 5. The slow dropping of pressurecaused by the leakage of air can continue only until a cer-' tain limit,depending upon the diameterof the cylinder i3 and the weight of the loadH, after which the load 5 8 begins to sink and to compress the-air tomake up the leakage losses. At the same time the sinking load willstretch the chain 9 thus effecting a graduated transition of the brakefrom pneumatic to gravity braking.

The restoration of. pressure in the main reservoir will automaticallyreturn the braking conditions from the gravity-actuated to air-actuatedbraking and the brake will become charged. The charging over of thebrake is not accompan- Every fault in the valve ll, in'the acceleratingvalve 29 or in the air conducting pipes will necessarily provoke fullbraking owing to the pressure drop in the release chamber B. Every faultin'the reservoir I4 will result in a smooth braking of the drum by theload ll. 7

Such a braking arrangement has the followving useful features that areespecially desirable does not reduce the mechanical braking effort butprevents a complete release and makes impossible the sinking and liftingoperations, since the complete release is only possible if an elevatedpressure exists in the chamber B.

2. The braking effect and the rate of its change corresponds strictlywith the change of position of the handle of the valve ll. The positionof this handle determines a given braking effect for an unlimited periodof time independently of any other conditions. This property of thebrake imparts to it an exceptional flexibility and ease of control andthe possibility of feeling the weight of the working tool in accordancewith the position of the valve handle at the beginning of the motion ofthe tool (at its sinking into the well).

Automatic drilling Having found (by turning the brake valve handle) therequired braking effort for the given sinking operation, we can obtain avery smooth, uniform, safe and easily adjustable movement of the sinkingtool towards the bottom of the well.

The adjustment offsinking movement of the tool against the bottom. ofthe well is being effected bymeans of a gradual release of the brakeuntil the rate ofrelease attains a value which is determined by theweight of the tools-and by the predetermined pressure exerted againstthe bottom. This release is effected by increasing the pressure in thereleasechamber B, for which purpose, as we know, the handle of the valveif is turned to the left. a

Engaging 0 the claw couplings The engaging of the claw couplings(Fig. 1) is effected by means of the cylinders 2H 22, 23 arranged asfollows:

The piston rod 2% of. the .cylinder 23 is connected to the fork of thecoupling. The piston 27 attached to the piston rod 26 carries thepacking sleeve 23. When engaging the coupling the recess of the piston2'? comes in contact with the rubber ring 25 provided in the cover 25which may be adjusted axially, for instance, by screwing it into thecylinder body 23. Thus is realized on the one hand the air-tight sealingat the engaged state of the coupling, and on the other hand the reliefof the coupling parts from destructive efforts developed during therotation and the prevention from sticking, because one can obtainbetween the claws a play equal to 1 or 2 millimeters. In the meantimethe possibility of a spontaneous disengaging of the claw couplings isexcluded. All the cylinders are controlled by means of the controllingvalve is and the starting valve 2h.

The cylinder 23 is shown in Fig. 1. It comprises the piston rod 24carrying the disc 27 which is provided with a ring edge Ma. The edge 21aof the disc 27 abuts against the rubber ring 2%, and in such manner theair-tightness of the cylinder is obtained and the stroke of. the pistonis limited.

The principle of operation has been explained above.

thereupon through 31 into the valve l9, and from this valve dependingupon its position through the pipes 38, 38, 40 into the slow speedcylinder'ZS, high speed cylinder 22, rotor 2| etc.

The valve 29 is actuated by a slight pressing on the foot pedal, therate of depressing, determining the air pressure and consequently theeffort acting on the engaging claws; thus it is possible to engage thecoupling with a slight pressing which may be augmented after thecoupling has engaged.

The principle of operation of the valve 20 is as follows: (see Fig. 2):

The main working parts of this valve are: the

inlet valve 55 which is forced. by the spring 50 toits seat (the bronzebushing 52). The lower tail portion of the valve i bears against themetal .disc 53 which is fastened to the leather diaphragm 54! providedwith openings for the passage of. air. This diaphragm adjoins to thehollow cap 56 consisting of two pieces interconnected by screwing,between which pieces an airtight diaphragm 55 is clamped.

The valve 253 operates in the following manner;

By depressing the foot pedal the hollow cap 56 is first forced againstthe leather diaphragm 54 and then together with that diaphragm ispressed against the valve 56. This valve compresses the spring 52] andis lifted upwards, so that air flowing from the main reservoir it to thestarting valve 29 (see Fig. 1) will pass (as indicated by an arrow onFig. 2) underneath the valve 5| into the cavity under the diaphragm 54and as shown by arrows will flow through the pipe 31 (Fig. 1) into thevalve l9. 7

Upon release of the foot pedal the cap 56 together with the diaphragms5i and 55 will retreat from the valve 5i, so that this valve will regainits seat 52 and will interrupt the admission of air. Thereupon due tothe air pressure the diaphragm 55 together with the cap 56 will retreatfrom the diaphragm 54 and the air will escape into the atmospherethrough the opening appearing in the cap 56 (as is shown by arrows).

The escape into the atmosphere may be obtained also by means of thevalve I9 (Fig. 1). This valve has the usual slide valve typearrangement, but the slide valve is of special design. The principle ofoperation of. the valve may be seen on Fig. 3. The face of the valve(51-62) has a number of through passages: the passage 6! communicateswith the inlet valve, the passage 58 with the atmosphere and otherpassages (57, 59, 62) communicate with respective cylinders which servefor engaging the claw couplings. The valve itself (63, M, 65) isprovided with a semi-annular recess 63 on its working surface and has aninner passage with two outlet openings M and 65. When the valve is inits closed position the recess [53 overlaps the openings 6i), 5?, 53, 59and $2 of the valve face so that they all communicate with each otherand with the outer air, whereas the air which is admitted by thestarting valve 2E3 (Fig. 1) into the opening 65 of the Valve it cannotpass into the opening 6 5. When turning the valve into a position, inwhich the opening 64 of the valve 00- incides (registers) with theopening 60 of the valve face, then the recess 63 will, as in the formercase, connect the openings 51, 59 and 62 with each other and with theouter air (through the opening 58) and to prevent the air from passinginto other cylinders which need not be actuated. The air which entersinto the opencoupling. Thus turning, the valve I9 into the positioncorresponding to one of the openings 61], 5?, 53 etc. (Fig. 3) andpressing upon the foot pedal of the'valve 2i. (Fig. 1) it'is possible toobtain the throwing in of the cylinder 2|, 22, to 'let air out into theatmosphere (through the passage 58) 'etc. Thus is facilitated andaccelerated the engaging of a coupling and at the same time a blockingaction is obtained preventing simultaneous actuating of two or morecylin-ders' (two or more claw couplings).

We claim:

7 1. A pneumatic control system for a drilling rig comprising arotatable member and a brake member adapted to be applied to or releasedfrom said rotatable member, a brake cylinder, a piston in said cylinderdividing the latter into two chamhers, means connecting said piston withsaid brake member, an air reservoir, means including a regulatingdevice,'and a non-return valve for maintaining the pressure in saidreservoir at a predetermined value; ,and'means connecting said reservoirwith one of said chambersiwhereby the piston is subjected to apredetermined air pressure constantly acting through said connectingmeans to apply said brake member.

2. A pneumatic control system as claimed in claim 1 characterized by theprovision of auxiliary actuating means connecting with said brake memberand operable to effectively apply the latter to the rotatable member,means con 'nected with said reservoir for counter-acting said auxiliaryactuating means, said actuating means being released on reduction of airpressure and acting to apply said brake member.

3. A pneumatic control system asclaimed in claim 1 characterized by theprovision of means connected with the other chamber for varying thepressure therein relatively to the pressure in the first mentionedchamber to cause displacement of the piston and the variableapplicationof the brake member, said last mentioned means including a manuallyoperable valve;

MATVEY ALCUNOVITCH CAPELIUSHNI COFF. SEMIEN LVOVITCI-I 'ZALKIN.

